Within the prior art are Hoppers for mining trucks, aggregate trucks in general, and train freight cars of different designs and shapes that are used to transport materials or mineral ore of differing granulometries, particle sizes and densities, which causes the volume or tonnage to differ depending of the latter parameter as regards an identical volume. The material hoppers are generally made of is structural steel and, in some cases, anti-abrasive steels, depending on the application and loading system. This latter point differs from each site, giving a better or worse condition with respect to the loading of the material, as loading through a chute, which is a rather gradual and controlled loading to a rather impact loading as would be the case of a front loader that projects the load by the sides of the truck, falling on the loading area or on the opposite side of the hopper, the operator's loosing sight of the equipment, and the welds that are used to join sides and floor or front and floor getting seriously damaged.
It turns out to be necessary, for all of the aforementioned conditions, to have stronger hoppers given current conditions and trends in the mining industry, which prefers larger equipment and greater loading capacity, with more equipment maintenance availability. To this effect, larger and stronger hoppers are required, reason by which they need a larger number of structures making them stronger and/or thicker in order to absorb impacts, in addition to increasing availability as a result of the wearing of the plates that are in contact with the material and aggregate's sliding upon emptying.
Current requirements of these load or hopper components force them to be sturdier, increasing its own weight along with a decrease in the material transported, depleting from the equipment (trucks or freight cars) loading capacity or, on the other hand, if a lighter hopper is made, sacrificing the thickness and materials of its structure, the frequency of its maintenance or replacements will have to be increased to cope with the decreased equipment availability due to frequent maintenance, neither of these scenarios is that users seek but the equilibrium of a hopper being able to resist loads and impacts and abrasion, and, in turn, light for its availability for corrective maintenance to be greater.
This utility model or invention is based on the use of state of the art or cutting edge technological elements in order to fulfill the objectives required by current market, achieving resistance to greater loading capacity without increasing its weight from structuring the unit or lengthen its useful life due to floor abrasion to meet availability as required by the customer.
In order to fulfill the resistance and availability requirements there presently exist special steels having greater structural resistance, from 300 MPa to 700 MPa resistance, depending on the type and origin. Our proposal is that of using steels having better mechanical properties, a structure being able to have equal or greater resistance without having to increase the thickness of the materials, since their densities do not vary much, in addition to making a design with computer design methods and tools currently available in order to simplify the structure, said structure being virtually analyzed fast and safely, which allows the making of steel folds at critical areas of the hopper which makes it more resistant. At the same time, in order for these folds to be made, more powerful and high-precision equipment is required, which forces us to use large folding-capacity technology having CNC's (Computer Numerical Controls) given the size of the precision pieces and the steels also require more power to fold due to their special properties.
On the other hand, in order to prevent abrasion wear, abrasion-resistant steels having hardness indices spanning from 200 current Brinell to 450 and/or 500, or over, being able to considerably increase the useful life against abrasion, but the resistance of which rises from about 800 Mpa to 1,400 Mpa, and over, are provided, which requires, moreover, the use of more robust equipment than traditionally, as was stated above. This allows to provide a highly resistant, highly available product for production, but having a low structural weight, thus allowing to transport larger loads and reduce the cost of fuel consumption, which, in large pieces of equipment, is a factor of considerable relevance.
Traditional manufacture of hoppers is based on very heavy structures having standards beams or folds. In some cases, special materials are used depending on the design, but they do not comply with the abovementioned objectives. As regards light hoppers, their weight is smaller in order not to reduce the truck's capacity, but have a shorter useful life due to shocks and/or abrasion, which forces the equipment to remain idle for more frequent maintenance.
As for applications of anti-abrasive steels, they are applied in their natural state as unfolded plates as a result of their high-resistance properties, and because making them with standard methods is very difficult.